This summer, Alexander Heffner, a 24-year-old journalist just a couple of years out of Harvard, became the host of a talk show on public television. But a new media venture this is not.

Mr. Heffner has slipped comfortably into the role of the host of “The Open Mind,” a program that made its debut during the Eisenhower administration with a format that has endured — a simple black backdrop, a guest and a host at a table and a discussion of topics like “Why Liberal Education Matters” and “Race and the Fourth Estate.”

He was born for the job, one might say — learning at the footsteps of his grandfather, Richard D. Heffner, a pioneer in broadcasting who hosted the show for 56 years, until his death in December. It has been broadcast for the last 34 years on the PBS station WNET (Channel 13) at noon on Saturday. It also is broadcast on CUNY-TV on Sundays and Mondays.

“My grandfather was my mentor,” Alexander Heffner said. “His conviction of the importance of public broadcasting and elevating our discourse into something substantive and meaningful were values that were instilled in me.”

Richard D. Heffner hosted the public affairs program “The Open Mind” for 56 years until his death in December at 88.CreditSara Krulwich/The New York Times

The elder Mr. Heffner gave significant, uninterrupted airtime to people and topics that were controversial, including Malcolm X, Helen Gurley Brown, McCarthyism and homosexuality.

The younger Mr. Heffner, who first appeared on “The Open Mind” as a guest in 2012 to talk about the presidential election while still a college student, says his focus is on finding a new generation of guests who will stand up over time and often discuss public policy from an oblique angle — musicians, technologists, humorists, as well as writers and university presidents.

Fascinated since childhood by broadcasting and civil discourse, Mr. Heffner hosted a public affairs radio show in high school and as an undergraduate. During school and since graduating, he has reported on young people in politics for newspapers and the PBS program “Need to Know.”

Elaine Heffner, a psychotherapist and the widow of Richard Heffner, is the executive producer of “The Open Mind.” She said her grandson would help bring the show to a new audience. “Part of reaching a new demographic is to evolve in the way you reach them,” she said. “You continue the name, meaning and content, but the form will evolve.”

Even before he became the host, Alexander Heffner said, he advised his grandfather to use social media to build the program’s audience. “When I said to him that we should create a Facebook page and Twitter feed, he said that is for you to do,” Mr. Heffner said. “He saw the potential for perpetuating the values he believed in, but it was a hard sell, due to our different vintage and his being steeped in the written word and the value of books.”

Still, a final act by Richard Heffner was to digitize and upload to the Internet much of “The Open Mind” archive of more than 1,500 episodes, many of which can be streamed.

In one episode from 2003, Richard Heffner had Adam Bellow, a son of Saul Bellow, appear to discuss the son’s book “In Praise of Nepotism.” Mr. Heffner said he would replace the term nepotism with “family values,” that is “loving one’s children; loving one’s relatives; loving one’s friends and being helpful to them.”

His grandson said he was not “joining the family business,” but “more like the family vision — the vision of communications and media serving the public interest.”